SF6 gas leakage monitoring and alarm system

installGIS room SF6 gas leakage monitoring and alarm systemThe necessity:

High voltage SF6 switchgear is filled with SF6 gas inside. SF6 gas is mainly used as an excellent insulation and arc extinguishing medium in the power industry and has been successfully applied to high-voltage switches and their equipment. In the fields of high voltage, ultra-high voltage, and extra high voltage, SF6 gas has almost become the insulation and arc extinguishing medium for circuit breakers and GIS.

However, during the switching operation, SF6 gas will decompose under factors such as arc action, corona, spark discharge, partial discharge, and high temperature. When it encounters moisture, its decomposition will become a corrosive electrolyte, including some highly toxic decomposition products such as SF4, S2F2, S2F10, SOF2, HF, and SO2, which can irritate the skin and mucous membranes. If inhaled in large amounts, it can also cause dizziness, emphysema, and even death. Equipment filled with SF6 gas is mostly installed indoors, where the air circulation speed is relatively slow. If SF6 gas leaks, it will deposit indoors and be difficult to dissipate. SF6 gas itself is colorless and odorless, making it difficult to detect leaks. In addition, due to the higher specific gravity of SF6 gas compared to oxygen, it often deposits in lower spaces, which can easily cause local hypoxia and suffocation. This will pose a great safety hazard to the on-site staff.

On the one hand, due to the excellent insulation and arc extinguishing characteristics of SF6, SF6 equipment has gradually been widely used in high and medium voltage fields. On the other hand, the possibility of SF6 gas itself causing harm to equipment, the environment, and especially the health and safety of on-site workers is also increasing. In order to ensure the normal and safe operation of the equipment and fully safeguard the physical health and safety of on-site personnel, effective measures must be taken to monitor SF6 gas leaks in the equipment area to prevent accidents from occurring.

The "Electricity Safety Work Regulations" (for power plants and substations) specifically stipulate that the distribution equipment room equipped with SF6 equipment must ensure that the SF6 gas concentration is less than 1000ppm. In addition to installing strong ventilation devices, it is also necessary to install oxygen meters and SF6 gas concentration monitoring alarm devices that can alarm.

Function of SF6 gas leakage monitoring and alarm system in GIS room:

According to the overall plan of the project,GIS room SF6 gas leakage monitoring and alarm systemIt mainly has the following functions:

1) Equipped with SF6 gas concentration exceeding detection and display function, polling detection and display of SF6 concentration at each gas detection unit in the switch room. When the concentration exceeds 1000ppm (can be set), a prompt alarm will be displayed and an alarm signal will be output;

2) It has the function of 02 concentration detection and display. It polls and detects the 02 concentration at each gas detection unit in the switch room. When the concentration is ≤ 18%, it displays a prompt alarm and outputs an alarm signal;

3) It has SF6 and 02 concentration control function. When the SF6 gas concentration exceeds or the 02 concentration is lower than the set value, the fan is controlled to start ventilation until the SF6 and 02 concentrations return to normal. Ventilation should continue for 15 minutes (adjustable);

4) It has the function of displaying the communication status of detection units, polling detection, and displaying the communication status between each detection unit and the host in the switch room. If a communication failure occurs, a prompt will be displayed;

5) Equipped with timed ventilation function, it can set up to 8 start and stop times;

6) It has a forced ventilation function. When the fan is in a stopped state, it can be controlled to perform forced ventilation for 15 minutes in the system. When the fan is turned on, it can be forcibly turned off in the system and the current operating status of the fan will be displayed on the screen;

7) Equipped with temperature and humidity detection and display, the system can measure and display the current temperature and humidity inside the switch room;

8) Equipped with fire linkage function and the ability to open and close this function;

9) Equipped with voice alarm function and the ability to turn it on and off, it will issue an alarm prompt when the SF6 or oxygen concentration in the environment exceeds the limit;

10) Equipped with human infrared sensing function, when workers enter and exit the monitored distribution room, the human infrared side detector can sense the entry and exit of workers within 5 meters around the host. At the same time, the system can automatically prompt the safety status of the environment;

11) Equipped with automatic data storage function, it can store historical data and prevent data loss in case of power failure;

12) It has the function of querying historical data and can enter the system interface through the menu to query the alarm data and continuous monitoring data for 5 years;

13) SF6 detection adopts imported infrared principle to ensure stable and reliable measurement data;

14) The entire system adopts a standard industrial bus network, which is easy to install, has a clear structure, and is stable and reliable;

15) Adopting a 7-inch LCD touch screen, providing a user-friendly human-computer interaction interface;

16) The volume of the device is small for installation;

17) All hardware is beautiful, generous, and easy to operate.